Kaptein YE, et al. - In non-ventilated acute decompensated heart failure (ADHF), subclavian vein (SCV) collapsibility index (CI) at 30–45° was identified to be correlated with paired inferior vena cava (IVC) CI, and could offer an alternative to IVC CI for evaluation of relative intravascular volume, which could facilitate clinical management.

• In this prospective analysis of non-ventilated ADHF patients who underwent paired IVC and SCV ultrasound assessments, the association between SCV CI and IVC CI was examined.

• This study included 33 patients with 36 encounters, SCV CI was found to be correlated with IVC CI during relaxed breathing and forced inhalation.

• SCV CI < 22% and >33% was shown to correspond to IVC CI < 20% and >50% indicating hypervolemia (sensitivity/specificity: 72%) and hypovolemia (sensitivity/specificity: 78%), respectively.

• Lower SCV CI and IVC CI were observed in relation to moderate to severe tricuspid regurgitation (TR) vs less than moderate TR.

• SCV CI and IVC CI did not differ significantly among chronic kidney disease stages.